arXiv AI

Overcoming Prior Barriers: Supervised Fine-Tuning under Long-Tail Distribution

The paper introduces the concept of a prior barrier to measure how well pretrained large language models support different concepts during supervised fine‑tuning (SFT). It shows that these barriers follow a long‑tail distribution, causing head concepts to be easier to learn than tail concepts. To address this, the authors propose PASS, an adaptive instruction‑selection method that allocates limited supervision budget toward under‑covered concepts, outperforming seven state‑of‑the‑art methods across multiple settings.

arXiv AI
Oct 12

What Should SFT Learn? Conditional Information Gain for Generalizable Post-Training

The paper introduces CIG‑SFT, a supervised fine‑tuning method that uses conditional information gain to evaluate how much each demonstrated token reduces uncertainty about the task. By comparing token likelihoods from a frozen reference model with and without task input, the method derives a KL‑regularized projection of the current policy, yielding a scalar‑weighted SFT objective whose gradients match the projected target. Experiments on mathematical reasoning and code‑generation benchmarks show that CIG‑SFT outperforms standard SFT and adaptive fine‑tuning baselines, especially in generalizing to challenging evaluation distributions, without requiring extra data or online rollouts.

By Yuxuan Gu, Kequan Niu, Xiaocheng Feng, Yun Li, Yiqiao Yang, Bing Qin
arXiv AI
Oct 9

SFT-as-Context Mitigates Forgetting in Supervised Fine-Tuning

The paper introduces SFT-as-context, a training‑free method that lets a parent large language model (LLM) use the response of a supervised fine‑tuned (SFT) model as context to answer queries. This approach preserves the parent model’s general capabilities while acquiring the SFT model’s specialized skills, achieving performance close to the SFT model on fine‑tuned benchmarks and near the parent model on general tasks. Experiments across 19 parent‑SFT pairs and 11 benchmarks show minimal gaps in performance, and the method can solve problems requiring both specialized and general knowledge, even when neither model alone succeeds.

By Kenan Tang, Andong Hua, Chengxuan Qian, Saket Tiwari, Yao Qin
arXiv AI
4d ago

Match the Canvas, Not Just the Answer: Predictability-Aware SFT for Diffusion Language Models

The paper introduces Predictability-Aware Canvas Selection and Supervision (PACS), a supervised fine‑tuning method for diffusion language models that aligns training with inference by using the model’s own predictability to determine which tokens are visible and when they are supervised. PACS selects the attention‑visible input length for each example and supervises reference tokens just before they become confident, addressing mismatches caused by random masking. Experiments on reasoning and code‑generation benchmarks show PACS consistently outperforms standard SFT, achieving up to 12.84 percentage‑point gains on individual tasks.

By Miao Li, Hanyang Jiang, Hengyu Fu, Baihe Huang, Yating Liu, Yuhang Cai, Changkun Guan, Zhongzhu Chen, Jiecheng Lu, Michael A. Boateng, Pascal Van Hentenryck
arXiv AI
Sep 3

Task-Level Natural Language Priors as Learning Signals for Low-Resource LLM Training

Task-Level Natural Language Priors as Learning Signals for Low-Resource LLM Training proposes Prior-Guided Tuning (PGT), a training approach that treats natural-language priors as auxiliary learning signals rather than just input context. The method introduces Contrastive Prior Steering (CPS), which adds positive and negative prior-conditioned auxiliary losses while preserving the original supervised objective. Experiments on AmbiMath, Jigsaw, and MNLI/HANS demonstrate that CPS consistently outperforms plain and prompt fine-tuning, achieving high accuracy and significant gains with limited training data.

By Jian Gao, Xiao Zhang, Xun Zhu, Miao Li, Ji Wu
arXiv AI
Sep 10

Explainable Token-level Noise Filtering for LLM Fine-tuning Datasets

The paper introduces XTF, an explainable token‑level noise filtering framework for fine‑tuning large language models. XTF breaks down token contributions into reasoning importance, knowledge novelty, and task relevance, scores them, and masks gradients of noisy tokens to improve fine‑tuning. Experiments on math, code, and medicine tasks across seven LLMs show up to a 13.7% performance boost over standard fine‑tuning.

By Yuchen Yang, Wenze Lin, Enhao Huang, Zhixuan Chu, Hongbin Zhou, Lan Tao, Yiming Li, Zhan Qin, Kui Ren
arXiv AI
Sep 3

DKL: Decoupled Knowledge Learning for Instruction-Tuned Language Models

The paper introduces DKL, a method for adding new knowledge to instruction‑tuned language models without compromising their instruction‑following abilities. DKL performs extended pre‑training on a base LLM to embed knowledge, then merges these weights into the instruction‑tuned model, avoiding costly instruction fine‑tuning. Experiments show DKL raises RAG accuracy from 54.17% to 79.26% on retrieval failure cases while using far less training data than previous approaches.

By Kushagra Bhushan, Meghanadh Pulivarthi, Sai Krishna Reddy Sathi, Gaurav Pandey, Sonam Gupta, Vineet Kumar, Jaydeep Sen, Yatin Nandwani, Sachindra Joshi, Dinesh Raghu